The Importance of Wild-Animal Suffering

First written: July 2009; Last edited: 24 May 2020

The number of wild animals vastly exceeds that of animals on factory farms, in laboratories, or kept as pets. Therefore, animal advocates should consider focusing their efforts to raise concern about the suffering that occurs in the natural environment. While in theory this could involve trying directly to engineer more humane ecological systems, in practice I think activists should concentrate on promoting the meme of caring about wild animals to other activists, academics, and other sympathetic groups. The massive amount of suffering occurring now in nature is indeed tragic, but it pales by comparison to the scale of good or harm that our descendants -- with advanced technological capability -- might effect. I fear, for instance, that future humans may undertake terraforming, directed panspermia, or sentient simulations without giving much thought to the consequences for wild animals. Our #1 priority should be to ensure that future human intelligence is used to prevent wild-animal suffering, rather than to multiply it.

Other versions

Summary of why suffering probably dominates happiness

I personally believe that most animals (except maybe those that live a long time, like >3 years) probably endure more suffering than happiness overall, because I would trade away several years of life to avoid the pain of the average death in the wild. And this hypothetical tradeoff assumes that animal lives prior to death are net positive (which is not obvious, in view of cold, hunger, disease, fear of predators, and all the rest).

However, this belief of mine is somewhat controversial. I think the claim of net expected suffering in nature needs only a weaker assertion: namely, that almost all of the expected happiness and suffering in nature come from small animals (e.g., minnows and insects). The adults of these species live at most a few years, often just a few months or weeks, so it's even harder in these cases for the happiness of life to outweigh the pain of death. Moreover, almost all the babies of these species die (possibly painfully) after just a few days or weeks of being born, because most of these species are "r-selected" -- see Type III in this chart.

See also:


"The total amount of suffering per year in the natural world is beyond all decent contemplation. During the minute it takes me to compose this sentence, thousands of animals are being eaten alive; others are running for their lives, whimpering with fear; others are being slowly devoured from within by rasping parasites; thousands of all kinds are dying of starvation, thirst and disease."

-- Richard Dawkins, River Out of Eden[Dawkins]

"Many humans look at nature from an aesthetic perspective and think in terms of biodiversity and the health of ecosystems, but forget that the animals that inhabit these ecosystems are individuals and have their own needs. Disease, starvation, predation, ostracism, and sexual frustration are endemic in so-called healthy ecosystems. The great taboo in the animal rights movement is that most suffering is due to natural causes."

-- Albert, a fictional dog in philosopher Nick Bostrom's "Golden"[Bostrom-Alfred]

"The moralistic fallacy is that what is good is found in nature. It lies behind the bad science in nature-documentary voiceovers: lions are mercy-killers of the weak and sick, mice feel no pain when cats eat them, dung beetles recycle dung to benefit the ecosystem and so on."

-- Steven Pinker[Pinker]

"People who accuse us of putting in too much violence, [should see] what we leave on the cutting-room floor."

-- David Attenborough, speaking about his nature documentaries[Attenborough]

"In sober truth, nearly all the things which men are hanged or imprisoned for doing to one another, are nature's every day performances. [...] The phrases which ascribe perfection to the course of nature can only be considered as the exaggerations of poetic or devotional feeling, not intended to stand the test of a sober examination. No one, either religious or irreligious, believes that the hurtful agencies of nature, considered as a whole, promote good purposes, in any other way than by inciting human rational creatures to rise up and struggle against them."

-- John Stuart Mill, "On Nature"[Mill]

Animal activists typically focus their efforts on areas where humans directly interact with members of other species, such as on "factory farms," in laboratory experiments, and, to a much lesser degree, in zoos, circuses, rodeos, and the like.

Rarely discussed is the topic of animal suffering in the wild, even in the academic literature, though there have been notable exceptions.[exceptions] In this piece, I emphasize that the numbers of wild animals on which humans have an impact is simply too large for animal advocates to ignore. Intense suffering is a regular feature of life in the wild that demands, perhaps not quick-fix intervention, but at least long-term research into the welfare of wild animals and technologies that might one day allow humans to improve it. I conclude by encouraging animal advocates to focus their efforts to promote concern about wild-animal suffering among other activists, academics, and others who would be sympathetic -- both to encourage research on the issue and to ensure that our descendants use their advanced technologies in ways that alleviate wild-animal suffering rather than inadvertently multiply it.

Numbers of Wild Animals

The scale of animal suffering at human hands is vast, and animal advocates are right to be appalled by its magnitude. However, the numbers of animals that live in the wild are staggeringly larger. For rough population estimates, see my "How Many Wild Animals Are There?"[Tomasik-numbers]

How Wild Animals Suffer

Like their domestic counterparts, animals in the wild have rich emotional lives.[emotions] Unfortunately, many of these emotions are intensely painful, often needlessly so. And while "Nature, red in tooth and claw" is widely known as a platitude, its visceral meaning can often be overlooked. Below I review some details of wild-animal suffering, perhaps in a manner similar to the way in which animal advocates decry acts of cruelty by humans.


When people imagine suffering in nature, perhaps the first image that comes to mind is that of a lioness hunting her prey. Christopher McGowan, for instance, vividly describes the death of a zebra:

The lioness sinks her scimitar talons into the zebra's rump. They rip through the tough hide and anchor deep into the muscle. The startled animal lets out a loud bellow as its body hits the ground. An instant later the lioness releases her claws from its buttocks and sinks her teeth into the zebra's throat, choking off the sound of terror. Her canine teeth are long and sharp, but an animal as large as a zebra has a massive neck, with a thick layer of muscle beneath the skin, so although the teeth puncture the hide they are too short to reach any major blood vessels. She must therefore kill the zebra by asphyxiation, clamping her powerful jaws around its trachea (windpipe), cutting off the air to its lungs. It is a slow death. If this had been a small animal, say a Thomson's gazelle (Gazella thomsoni) the size of a large dog, she would have bitten it through the nape of the neck; her canine teeth would then have probably crushed the vertebrae or the base of the skull, causing instant death. As it is, the zebra's death throes will last five or six minutes.[McGowan, pp. 12-13]

Some predators kill rather quickly, such as constrictor snakes that cut off their victims' air flow and induce unconsciousness within a minute or two,[eaten-alive] while others impose a more protracted death, such as hyenas that tear off chunks of ungulate flesh one bite at a time.[Kruuk] Wild dogs disembowel their prey,[McGowan, p. 22] venomous snakes cause internal bleeding and paralysis over the course of several minutes,[McGowan, pp. 49] and crocodiles drown large animals in their jaws.[McGowan, pp. 43]

One snake owner's guide explains, "Live mice will fight for their lives when they are seized, and will bite, kick and scratch for as long as they can."[Flank] Once captured, "The snake drenches the prey with saliva and eventually pulls it into the esophagus. From there, it uses its muscles to simultaneously crush the food and push it deeper into the digestive tract, where it is broken down for nutrients."[Perry]

Prey may not die immediately after being swallowed, as is illustrated by the fact that some poisonous newts, after ingestion by a snake, excrete toxins to kill their captor so that they can crawl back out of its mouth.[McGowan, pp. 59] And regarding housecats, Bob Sallinger of the Audubon Society of Portland remarked, "People who are appalled by the indiscriminate killing of wildlife by mechanisms such as leg-hold traps should recognize that the pain and suffering caused by cat predation is not dissimilar and the impacts of cat predation dwarf the impacts of trapping."[Sallinger]

It's possible that some animals don't suffer intensely from predation in cases where endorphins kick in strongly enough. Similarly, humans sometimes don't feel pain immediately upon severe injury.[Wall] But in many instances of predation, prey continue struggling violently against their aggressors. For instance, in this video, the warthog screams for ~2.5 minutes as it's suffocated. Moreover, insofar as endorphins do sometimes reduce the painfulness of death, the same argument should apply for brutal slaughter of farm animals by humans, yet most animal-welfare scientists consider bad slaughter methods to be extremely painful.

Fear of predators produces not only immediate distress, but it may also cause long-term psychological trauma. In one study of anxiolytics, researchers exposed mice to a cat for five minutes and observed subsequent reactions. They found "that this animal model of exposure of mice to unavoidable predatory stimuli produces early cognitive changes analogous to those seen in patients with acute stress disorder (ASD)."[ElHagePeronnyGriebelBelzung] A follow-up study found long-term impacts on the mice's brains: "predatory exposure induced significant learning disabilities in the radial maze (16 to 22 days poststressor) and in the spatial configuration of objects recognition test (26 to 28 days poststressor). These findings indicate that memory impairments may persist for extended periods beyond a predatory stress."[ElHageGriebelBelzung] Similarly, Phillip R. Zoladz exposed rats to unavoidable predators and other anxiety-causing conditions to "produce changes in rat physiology and behavior that are comparable to the symptoms observed in PTSD patients."[Zoladz] And in a review article, Rianne Stam explained:

Animal models that are characterised by long-lasting conditioned fear responses as well as generalised behavioural sensitisation to novel stimuli following short-lasting but intense stress have a phenomenology that resembles that of PTSD in humans. [...] Weeks to months after the trauma, treated animals on average also show a sensitisation to novel stressful stimuli of neuroendocrine, cardiovascular and gastrointestinal motility responses as well as altered pain sensitivity and immune function.[Stam]

Even for those prey that haven't had a traumatic run-in with a predator, the "ecology of fear" that predators create can be very distressing: "In studies with elk, scientists have found that the presence of wolves alters their behavior almost constantly, as they try to avoid encounters, leave room for escape and are constantly vigilant."[Stauth]

One can advance some argument that evolution should avoid making animal lives excessively horrifying for extended periods prior to death because doing so might, at least in more complex species, induce PTSD, depression, or other debilitating side-effects. Of course, we see empirically that evolution does induce such disorders when traumatic incidents happen, like exposure to a predator. But there's probably some kind of reasonable bound on how bad these can be most of the time if animals are to remain functional. Death itself is a different matter because, once it reaches the point of inevitability, evolutionary pressures don't constrain the emotional experience. Death can be as good as painless (for a few lucky animals) or as bad as torture (for many others). Evolution has no reason to prevent death from feeling unbearably awful.[Dawkins]

Death by Other Means

Of course, predation is not the only way in which organisms die painfully.

Animals are also stricken by diseases and parasites, which may induce listlessness, shivering, ulcers, pneumonia, starvation, violent behavior, or other gruesome symptoms over the course of days or weeks leading up to death. Avian salmonellosis is just one example:

Signs range from sudden death to gradual onset of depression over 1 to 3 days, accompanied by huddling of the birds, fluffed-up feathers, unsteadiness, shivering, loss of appetite, markedly increased or absence of thirst, rapid loss of weight, accelerated respiration and watery yellow, green or blood-tinged droppings. The vent feathers become matted with excreta, the eyes begin to close and, immediately before death, some birds show apparent blindness, incoordination, staggering, tremors, convulsions or other nervous signs.[Salmonellosis]

Still other animals die of accidents, dehydration during a summer drought, or lack of food during the winter. For instance, 2006 was a harsh year on bats in Placerville, California:

"You can see their ribs, their backbones, and (the area) where the intestine and the stomach are is completely sunk through to the back," said Dharma Webber, founder of the California Native Bat Conservancy. [...] She said emerging mosquitoes aren't enough to feed the creatures. "It would be like us eating a little piece of popcorn here or there," she said.[bats]

(Of course, when the bats do have food, this isn't good news for their prey....)

Even ice storms can be fatal: "Birds unable to find a sheltered perch during the storm may have their feet frozen to a branch or their wings covered in ice making them unable to fly. Grouse buried in snow drifts are often encased by the ice layer and suffocate."[Heidorn]

A Hard Life

While death may often constitute the peak of suffering during an animal's life, day-to-day existence isn't necessarily pleasant either. Unlike most humans in the industrialized world, wild animals don't have immediate access to food whenever they become hungry. They must constantly seek out water and shelter while remaining on the lookout for predators. Unlike us, most animals can't go inside when it rains or turn on the heat when winter temperatures drop far below their usual levels. In summary:

It is often assumed that wild animals live in a kind of natural paradise and that it is only the appearance and intervention of human agencies that bring about suffering. This essentially Rousseauian view is at odds with the wealth of information derived from field studies of animal populations. Scarcity of food and water, predation, disease and intraspecific aggression are some of the factors which have been identified as normal parts of a wild environment which cause suffering in wild animals on a regular basis.[UCLA, p. 24]

And while many animals appear to endure such conditions rather calmly, this doesn't necessarily mean they aren't suffering.[BourneEtAl] Sick and injured members of a prey species are the easiest to catch, so predators deliberately target these individuals. As a consequence, those prey that appear sick or injured will be the ones killed most often. Thus, evolutionary pressure pushes prey species to avoid drawing attention to their suffering.[Nuffield, ch. 4.12, p. 66]

Based on studies of stress-hormone levels in domestic and wild animals, Christie Wilcox[Wilcox] concluded that "if we follow the guidelines of care that provide food, water, comfort, and necessary items for behavioral expression, domesticated animals are not only likely to be as happy as their wild relatives, they're probably happier." She also observed:

So the real question becomes whether a domesticated or captive animal is more, less, or as happy in the moment as its wild counterpart. There are a few key conditions that are classically thought to lead to a "happy" animal by reducing undue stress. These are the basis for most animal cruelty regulations, including those in the US and UK. They include that animals have the 'rights' to:

- Enough food and water

- Comfortable conditions (temperature, etc)

- Expression of normal behavior

When it comes to wild animals, though, only the last is guaranteed. They have to struggle to survive on a daily basis, from finding food and water to another individual to mate with. They don't have the right to comfort, stability, or good health. [...] By the standards our governments have set, the life of a wild animal is cruelty.

Short Lifespans

In nature, the most populous animals are probably the ones that are generally worst off. Small mammals and birds have adult lifespans at most one or three years before they face a painful death. And many insects count their time on Earth in weeks rather than years -- for instance, just 2-4 weeks for the horn fly.[Cumming] I personally would prefer not to exist than to find myself born as an insect, struggle to navigate the world for a few weeks, and then die of dehydration or be caught in a spider's web. Worse still might be finding myself entangled in an Amazonian-ant "torture rack" trap for 12 hours,[BBC] or being eaten alive over the course of weeks by an Ichneumon wasp.[Gould, pp. 32-44] (That said, whether caterpillars eaten by Ichneumon wasps feel pain during the experience is unclear.)

It's true that scientists remain uncertain whether insects experience pain in a form that we would consider conscious suffering.[insect-pain] However, the fact that there remains serious debate on the issue suggests that we should not rule out the possibility. And seeing as insects number 1018,[Williams] with the number of copepods in the ocean of a similar magnitude,[SchubelButman] the mathematical "expected value" (probability times amount) of their suffering is vast. I should note that the force of this point would be lessened if, as may be the case, an animal's "intensity" or "degree" of emotional experience depends to some rough extent on the amount of neural tissue it has devoted to pain signals.

More Offspring Than Survive

Tables of animal lifespans typically show durations of survival by adult members of a species. However, most individuals die much sooner, before reaching maturity. This is a simple consequence of the fact that females give birth to far more offspring than can survive to reproduce in a stable population. For instance, while humans can produce only one child per reproductive season (excepting twins), the number is 1-22 offspring for dogs (Canis familiaris), 4-6 eggs for the starling (Sturmus vulgaris), 6,000-20,000 eggs for the bullfrog (Rana catesbeiana), and 2 million eggs for the scallop (Argopecten irradians).[SolbrigSolbrig, p. 37] Take a look at this figure from Thomas J. Herbert's article[Herbert] on r and K selection illustrating extremely high infant mortality for "r strategists." Most small animals like minnows and insects are r strategists.

Granted, it's unclear whether all of these species are sentient -- and even more regarding that fraction of the eggs that fails to hatch (see the next section) -- but again, in expected-value terms, the amount of expected suffering is enormous.

This strategy of "making lots of copies and hoping a few come out" may be perfectly sensible from the standpoint of evolution, but the cost to the individual organisms is tremendous. Matthew Clarke and Yew-Kwang Ng conclude from an analysis of the welfare implications of population dynamics that "The number of offspring of a species that maximizes fitness may lead to suffering and is different from the number that maximizes welfare (average or total)."[ClarkeNg, sec. 4]

In a related paper, "Towards Welfare Biology: Evolutionary Economics of Animal Consciousness and Suffering," Ng concludes from the excess of offspring over adult survivors: "Under the assumptions of concave and symmetrical functions relating costs to enjoyment and suffering, evolutionary economizing results in the excess of total suffering over total enjoyment."[Ng, p. 272] (Update: In 2019, Zach Groff and Ng showed that this theorem contains a mathematical error, and a stronger starting premise is needed to conclude that suffering predominates.[Groff and Ng] I haven't looked into this issue in depth, but you can see some initial thoughts of mine here and here.)

In his famous paper, "Animal liberation and environmental ethics: Bad marriage, quick divorce,"[Sagoff] Mark Sagoff quotes the following passage from Fred Hapgood:[Hapgood]

All species reproduce in excess, way past the carrying capacity of their niche. In her lifetime a lioness might have 20 cubs; a pigeon, 150 chicks; a mouse, 1000 kits; a trout, 20,000 fry, a tuna or cod, a million fry or more; [...] and an oyster, perhaps a hundred million spat. If one assumes that the population of each of these species is, from generation to generation, roughly equal, then on average only one offspring will survive to replace each parent. All the other thousands and millions will die, one way or another.1

Sagoff goes on to say: "The misery of animals in nature--which humans can do much to relieve--makes every other form of suffering pale in comparison. Mother Nature is so cruel to her children she makes Frank Perdue look like a saint."

When Do Babies Become Sentient?

The previous section explained that in r-selected species, parents may have hundreds or even tens of thousands of offspring, and almost all of these die shortly after birth.

But some questions remain. What fraction of these offspring were sentient at the time of death, and what fraction merely died as unconscious eggs or larvae?

EFSA's "Aspects of the biology and welfare of animals used for experimental and other scientific purposes" (pp. 37-42) explores when fetuses of various species begin to feel conscious pain.[EFSA] The paper notes that the age of onset of consciousness varies based on whether a species is precocial (well developed at birth, such as horses) or altricial (still developing at birth, such as marsupials). Precocial animals are more likely to feel pain at earlier ages. Also relevant is whether the species is viviparous (having live birth) or oviparous (giving birth through eggs). Viviparous animals have greater need to inhibit fetal consciousness during development in order to prevent injury to the mother and siblings. Oviparous animals that are constrained by shells have less need for inhibition of awareness before birth. (p. 38)

For this reason, the report suggests: "If awareness is the criterion for protection, birds, reptiles, amphibians, fish and cephalopods may, therefore, be more obviously in need of protection pre-hatching than mammals are in need of protection pre-partum." (p. 38) For example: "Sensory and neural development in a precocial bird such as the domestic chick is very well advanced several days before hatching. Controlled movements and coordinated behavioural and electrophysiological evoked responses to tactile, auditory and visual stimuli appear three or four days before hatching occurs after 21 days of incubation (Broom, 1981)." (p. 39) In contrast: "Even though the mammalian fetus can show physical responses to external stimuli, the weight of present evidence suggests that consciousness does not occur in the fetus until it is delivered and starts to breathe air." (p. 42)

Thus, it seems clear that many animals are able to suffer by the time of birth if not before.

The stage of development at which this risk [of suffering] is sufficient for protection to be necessary is that at which the normal locomotion and sensory functioning of an individual independent of the egg or mother can occur. For air-breathing animals this time will not generally be later than that at which the fetus could survive unassisted outside the uterus or egg. For most vertebrate animals, the stage of development at which there is a risk of poor welfare when a procedure is carried out on them is the beginning of the last third of development within the egg or mother. For a fish, amphibian, cephalopod, or decapod it is when it is capable of feeding independently rather than being dependent on the food supply from the egg. [...] (p. 3)

Most amphibians and fish have larval forms which are not well developed at hatching but develop rapidly with experience of independent life[.] Those fish and amphibians that are well developed at hatching or viviparous birth and all cephalopods, since these are small but well developed at hatching, will have had a functioning nervous system and the potential for awareness for some time before hatching. (p. 38)

Another consideration suggestive of pain before birth is the fact that many oviparous vertebrates can hatch early in response to environmental stimuli, including vibrations that feel like a predator.

For example, for skink eggs: "Simulated predation experiments in the field induced hatching in both nest sites (horizontal rock crevices) and in eggs displaced from nest sites. The hatching process was explosive: early hatching embryos hatched in seconds and sprinted from the egg an average of 40 cm as they hatched."[DoodyPaull] Early hatching has also been documented for amphibians, fish, and invertebrates.[DoodyPaull]

Young fish are already intelligent enough to be predators a few days after birth: "In the Sacramento-San Joaquin Estuary, young striped bass begin feeding on small crustacean zooplankton a few days after they hatch (Eldridge et al. 1982)."[StevensEtAl, pp. 21-22] Unfortunately, huge numbers of striped bass die young, given that "the average female striped bass produc[es] nearly a half million eggs".[StevensEtAl, p. 20]

These points suggest that a significant fraction of the large numbers of offspring born to r-selected species may very well be conscious during the pain of their deaths after a few short days, or even hours, of life.

Misjudging Levels of Well-Being?

There is a danger in extrapolating the welfare of wild animals from our own imagination of how we would feel in the situation. We can imagine immense discomfort were we to sleep through a cold winter night's storm with only a sweatshirt to keep us warm, but many animals have better fur coats and can often find some sort of shelter. More generally, it seems unlikely that species would gain an adaptive advantage by feeling constant hardship, since stress does entail a metabolic cost.[Ng] Also, r-selected animals might suffer less from a given injury than long-lived animals would because r-selected creatures have less to lose by taking big short-term risks.[Tomasik-short-lived]

That said, we should also be wary of underestimating the extent and severity of wild-animal suffering due to our own biases. You, the reader, are probably in the comfort of a climate-controlled building or vehicle, with a relatively full stomach, and without fear of attack. Most of us in the industrialized West go through life in a relatively euthymic state, and it's easy to assume that the general pleasantness with which life greets us is shared by most other people and animals. When we think about nature, we may picture chirping songbirds or frolicking gazelles, rather than deer having their flesh chewed off while conscious or immobilized raccoons afflicted by roundworms. And of course, all of the previous examples, insofar as they involve large land animals, reflect my human tendency toward the "availability heuristic": In fact, the most prevalent wild animals of all are small organisms, many ocean-dwelling. When we think "wild animals," we should (if we adopt the expected-value approach to uncertainty about sentience) picture ants, copepods, and tiny fish, rather than lions or gazelles.

People may not accurately assess at a single instant how they'll feel overall during a longer period of time.[KahnemanSugden] They often exhibit "rosy prospection" toward future events and "rosy retrospection" about the past, in which they assume that their previous and future levels of wellbeing were and will be better than what's reported at the time of the experiences.[MitchellThompson] Moreover, even when organisms do correctly judge their hedonic levels, they often show a "will to live" quite apart from pleasure or pain. Animals that, in the face of lives genuinely not worth living, decide to end their existence tend not to reproduce very successfully.

Ultimately, though, regardless of exactly how good or bad we assess life in the wild to be on balance, it remains undeniable that many animals in nature endure some dreadful experiences.

If Life in Nature is so Bad, Why Don't Wild Animals Kill Themselves?

  1. Don't understand suicide: It may be that most animals (except the smartest mammals and birds?), while conscious emotionally, don't understand death. As an analogy, when I have a nightmare, I feel bad, but I don't fully realize I'm dreaming and am not sufficiently in control of the situation that I can end the nightmare at will. I guess non-dreaming animals do have more control over their physical state than I do when asleep, but the point is that you can have emotions without understanding life and death.
  2. Little to be gained when most suffering comes from death anyway: Animals don't have painless ways to kill themselves. For many animals, I think most of the total pain of their lives comes from dying. For example, many of the hundreds of offspring of a beetle mother will die within a few days or weeks of hatching. I think their lives up to the point of death might hover around being neutral between pain and happiness, so there's not much to be gained by early suicide.
  3. Temporal discounting: An animal often fails to act in its long-term hedonic interest due to short-sightedness. Even if suicide were optimal, the animal might not kill itself because doing so would be painful in the short run. (For example, when very nauseous, it may feel better to vomit immediately than to endure nausea for two hours going forward, but I can never muster up the courage to vomit.)
  4. Non-hedonic "will to live": I think animals have a "will to live" that's partly separate from their hedonic well-being. Animal behaviors are integrations of huge numbers of signals and brain systems, so it's not surprising that some of these systems act contrary to the hedonic-welfare-maximization systems. If animals did not have a “will to live”, presumably they would not survive as effectively.
  5. Few suicides on factory farms: If animals do kill themselves when their lives are not worth living, why don't we see more suicides on factory farms? Perhaps at least battery-cage hens would be better off killing themselves? (That said, Howie Lempel pointed out to me that maybe caged animals are less able to hurt themselves than free animals.)
  6. Big animals may have decent lives: I think the animals that potentially could contemplate suicide (chimpanzees??) likely do have lives worth living a good amount of the time.

Finally, there are some claims that animals do commit suicide, though others are doubtful. I'm personally skeptical because there aren't lots of well documented cases of animal suicide, and it's easy to accumulate folklore about phenomena that aren't real. That said, I don't doubt that some animals act differently when suffering an emotional loss.

But Can Humans Reduce Wild-Animal Suffering?

Why, then, is the suffering of wild animals not a top priority for animal advocates? One reason is philosophical: Some feel that while humans have duties to treat well the animals that they use or live with, they have no responsibility to those outside their sphere of interaction. I find this unsatisfying; if we really care about animals because we don't want fellow organisms to suffer brutally -- not just because we want to "keep our moral house clean" -- then it shouldn't matter whether we have a personal connection with wild animals or not.

Other philosophers agree with this but continue to defend human inaction by claiming that people are ultimately helpless to change the situation. When asked whether we should stop lions from eating gazelles, Peter Singer replied:

[...] for practical purposes I am fairly sure, judging from man's past record of attempts to mold nature to his own aims, that we would be more likely to increase the net amount of animal suffering if we interfered with wildlife, than to decrease it. Lions play a role in the ecology of their habitat, and we cannot be sure what the long-term consequences would be if we were to prevent them from killing gazelles. [...] So, in practice, I would definitely say that wildlife should be left alone.[Singer]

I would point out in response to Singer that most human interventions have not been designed to improve wild-animal welfare, and even so, I suspect that many of them have decreased wild-animal suffering on balance by reducing habitats.

In a similar vein as Singer, Jennifer Everett suggested that consequentialists may endorse evolutionary selection because it eliminates deleterious genetic traits:

[...] if propagation of the "fittest" genes contributes to the integrity of both predator and prey species, which is good for the predator/prey balance in the ecosystem, which in turn is good for the organisms living in it, and so on, then the very ecological relationships that holistic environmentalists regard as intrinsically valuable will be valued by animal welfarists because they conduce ultimately, albeit indirectly and via complex causal chains, to the well-being of individual animals.[Everett, p. 48]

These authors are right that consideration of long-range ecological side-effects is important. However, it does not follow that humans have no obligations regarding wild animals or that animal supporters should remain silent about nature's cruelty. The next few subsections elaborate on ways in which humans can indeed do something about wild-animal suffering.

Humans Already Impact Nature

I agree that we should be cautious about quick-fix intervention. Ecology is extremely complicated, and humans have a long track record of underestimating the number of unanticipated consequences they will encounter in trying to engineer improvements to nature. On the other hand, there are many instances in which we are already interfering with wildlife in some manner. As Tyler Cowen observed:[Cowen, p. 10]

In other cases we are interfering with nature, whether we like it or not. It is not a question of uncertainty holding us back from policing, but rather how to compare one form of policing to another. Humans change water levels, fertilize particular soils, influence climatic conditions, and do many other things that affect the balance of power in nature. These human activities will not go away any time soon, but in the meantime we need to evaluate their effects on carnivores and their victims.

One such evaluation was actually carried out regarding an Australian government decision to cull overpopulated and starving kangaroos at an Australian Defense Force army base.[ClarkeNg] While admittedly crude and theoretical, the analysis proves that the tools of welfare economics can be combined with the principles of population ecology to reach nontrivial conclusions about how human interference with wildlife affects aggregate animal well-being.

Consider another example. Humans spray 3 billion tons of pesticides per year,[Pimentel] and whether or not we think this causes more wild-animal suffering than it prevents, large-scale insecticide use is, to some extent, a fait accompli of modern society. If, hypothetically, scientists could develop ways to make these chemicals act more quickly or less painfully, enormous numbers of insects and larger organisms could be given slightly less agonizing deaths. (Note that pesticides might actually prevent net insect suffering if they reduce insect populations enough, so encouraging humane insecticides is not equivalent to encouraging less pesticide use. Indeed, organic farms may contain high amounts of insect suffering, both because of higher total fauna populations and because organic pest-control methods may be quite painful. I remain very uncertain on this question, though.)[Tomasik-insecticides]

Human changes to the environment -- through agriculture, urbanization, deforestation, pollution, climate change, and so on -- have huge consequences, both negative and positive, for wild animals. For instance, "paving paradise [or, rather, hell?] to put up a parking lot" prevents the existence of animals that would otherwise have lived there. Even where habitats are not destroyed, humans may change the composition of species living in them. If, say, an invasive species has a shorter lifespan and more non-surviving offspring than the native counterpart, the result would be more total suffering. Of course, the opposite could just as easily be the case.

Caring about wild-animal suffering should not be mistaken as general support for environmental preservation; indeed, in some or even many cases, preventing existence may be the most humane option. Consequentialist vegetarians ought not find this line of reasoning unusual: The utilitarian argument against factory farming is precisely that, e.g., a broiler hen would be better off not existing than suffering in cramped conditions for 45 days before slaughter. Of course, even in the calculation of whether to adopt a vegetarian diet, the impacts on animals in the wild can be important and sometimes dominant over the direct effects on livestock themselves.[MathenyChan]

That said, before we become too gung ho about eliminating natural ecosystems, we should also remember that many other humans value wilderness, and it's good to avoid making enemies or tarnishing the suffering-reduction cause by pitting it in direct opposition to other things people care about. In addition, many forms of environmental preservation, especially reducing climate change, may be important to the far future, by improving prospects for compromise among the major world powers that develop artificial general intelligence.

A Research Agenda

Wild-animal suffering deserves a serious research program, devoted to questions like the following:

  • What animals are sentient? What reasonable subjective probabilities should we use for the sentience of reptiles, amphibians, fish, and various invertebrates?
  • What sorts of affective states do animals experience during the course of everyday life in the wild? How often do they feel hunger, cold, fear, happiness, satisfaction, boredom, and intense agony, and to what degrees? Pablo Stafforini has suggested that it may one day become possible to answer this question with high precision through wearable continuous measurement devices recording neural correlates of hedonic experience. But until then, we can also benefit greatly by applying standard tools for assessing animal welfare.[Broom]
  • What is the overall balance of happiness versus suffering for various species? How does this depend on the animal's lifespan and whether it dies before maturity? Are certain species happier than others? Do certain types of ecosystems contain less total suffering than others? Which environmental-preservation efforts increase and which decrease aggregate animal welfare?
  • Are there long-term technologies that could eventually enable humans successfully to reduce wild-animal suffering in a serious way?

Advanced Technologies?

Humans presently lack the knowledge and technical ability to seriously "solve" the problem of wild-animal suffering without potentially disastrous consequences. However, this may not be the case in the future, as people develop a deeper understanding of ecology and welfare assessment.

If sentience is not rare in the universe, then the problem of wild-animal suffering extends beyond our planet. If it's improbable that life will evolve the type of intelligence that humans have,[Drake] we might expect that most of the extraterrestrials in existence are at the level of the smallest, shortest-lived creatures on earth. Thus, if humans ever do send robotic probes into space, there might be great benefit in using them to help wild animals on other planets. (One hopes that objections by deep ecologists to intervening in extraterrestrial ecosystems would be overcome.)

However, I should note that faster technological progress in general is not necessarily desirable. Especially in fields like artificial intelligence and neuroscience, faster progress may accelerate risks of suffering of other kinds. As a general heuristic, I think it may be better to wait on developing technologies that unleash vast amounts of new power before humans have the social institutions and wisdom to constrain misuse of this power.

Inadvertently Multiplying Suffering

While advanced future technologies could offer promise for helping wild animals, they also carry risks of multiplying the cruelty of the natural world. For instance, it's conceivable that humans could one day spread Earth-like environmental conditions to Mars in the process of "terraforming."[Burton] More speculatively, others have proposed "directed panspermia": dispatching probes into the galaxy to seed other planets with biological material.[Meot-NerMatloff] Post-human computer simulations may become sufficiently accurate that the wild-animal life they contain would consciously suffer. Already we see many simulation models of natural selection, and it's just a matter of time before these are augmented with AI capabilities such that the organisms involved become sentient and literally feel the pain of being injured and killed. Any of these possibilities would have prodigious ethical implications, and I do hope that before undertaking them, future humans consider seriously the consequences of such actions for the creatures involved.

Activists Should Focus on Outreach

What does all of this imply for the animal-advocacy movement? I think the best first step toward reducing wild-animal suffering that we can take now is to promote general concern for the issue. Causing more people to think and care about wild-animal suffering will hasten developments in research on wild-animal welfare and associated humane technologies, while at the same time helping to ensure that our advanced descendants think cautiously about actions that would create vastly more suffering organisms.

Perhaps finding supporters within the animal-advocacy community would be a good starting point. While some activists oppose all human intervention with the affairs of animals, occasionally even preferring that humans didn't exist, many people who feel humane sympathy for the suffering of members of other species should welcome efforts to prevent cruelty in the wild. It's important to ensure that the animal-rights movement doesn't end up increasing support for wilderness preservation and human non-interference of all kinds. Another potential source of supporters could be people interested in evolution, who recognize what Richard Dawkins has called the "blind, pitiless indifference" of natural selection.[Dawkins, p. 133]

Individuals can do much to raise the issue on their own, such as by

  • posting on animal-rights forums and writing blog comments;
  • participating in animal-rights meetups / events and asking attendees what they think;
  • writing conference papers, journal articles, or books on the topic (perhaps co-authored with ecologists, ethologists, or other scientists, to ensure that the work is not entirely armchair philosophy).

There may be a danger here of raising the wild-animal issue before the general public is ready. Indeed, the cruelty of nature is often used as a reductio by meat-eaters against consequentialist vegetarianism. Suggesting that ethical consideration for animals could require us to expend resources toward long-term research aimed at helping wildlife might turn off entirely people who would otherwise have given some consideration to at least those animals that they affect through dietary choices.[Greger]

I think wild-animal outreach should begin within communities that are most receptive, such as philosophers, animal activists, transhumanists, and scientists. We can plant the seeds of the idea so that it can grow into a component of the animal-rights movement. I also think a "don't spread wild-animal suffering to space" message could appear even in venues like TED or Slate precisely because it's a controversial idea that people haven't heard before. For those audiences, the message would appear in "far mode," wouldn't interfere with audience members' daily lives, and therefore could be entertained with less resistance.

It's true that most people are not in a position to endorse the moral urgency of reducing wild-animal suffering just yet. They may require earlier inferential steps first, such as caring about any non-human animals at all. The animal movement is like a worm: Each body part needs to slowly scooch its way forward to the next step. But the worm's head also needs to point in the right direction. Inspiring greater concern for wild animals among those who are ready for the message is like influencing where the worm's head points.

It's crucial that at some point the animal-rights movement moves beyond farm, laboratory, and companion animals. The scale of brutality in nature is too vast to ignore, and humans have an obligation to exercise their cosmically rare position as both intelligent and empathetic creatures to reduce suffering in the wild as much as they can.


[Dawkins] Dawkins, Richard. River Out of Eden. New York: Basic Books, 1995.

[Bostrom-Alfred] Bostrom, Nick. "Golden." 2004.

[Pinker] Sailer, Steve. "Q&A: Steven Pinker of 'Blank Slate.'" United Press International. 30 Oct. 2002. Accessed 17 Jan. 2014.

[Attenborough] Rustin, Susanna. "David Attenborough: 'I'm an essential evil.'" The Guardian. 21 Oct. 2011. Accessed 9 Jan. 2014.

[Mill] Mill, John Stuart. "On Nature." 1874. In Nature, The Utility of Religion and Theism, Rationalist Press, 1904.

[exceptions] Examples include (1) Sapontzis, Steve F. "Predation." Ethics and Animals 5.2 (1984): 27-38. (2) Naess, Arne. "Should We Try To Relieve Clear Cases of Extreme Suffering in Nature?" Pan Ecology 6.1 (1991). (3) Fink, Charles K. "The Predation Argument." Between the Species 5 (2005).

[Tomasik-numbers] Tomasik, Brian. "How Many Wild Animals Are There?" Essays on Reducing Suffering. 2009.

[emotions] See, for instance, (1) Balcombe, Jonathan. Pleasurable Kingdom: Animals and the Nature of Feeling Good. Palgrave Macmillan, 2006. (2) Bekoff, Marc, ed. The Smile of a Dolphin: Remarkable Accounts of Animal Emotions. Discovery Books, 2000.

[McGowan] McGowan, Christopher. The Raptor and the Lamb: Predators and Prey in the Living World. New York: Henry Holt and Company, 1997.

[eaten-alive] Eaten Alive - The World of Predators. Questacon on Tour.

[Kruuk] Kruuk, H. The Spotted Hyena. Chicago: University of Chicago Press, 1972.

[Flank] Flank, Lenny. "Live Prey vs. Prekill." The Snake: An Owner's Guide To A Happy Healthy Pet. Howell Book House, 1997.

[Perry] Perry, Lacy. "How Snakes Work: Feeding."

[Sallinger] Sallinger, Bob. "Audubon Society Favors Keeping Cats Indoors." The Oregonian. 17 Nov. 2003.

[Wall] Wall, Patrick. Pain: The Science of Suffering. New York: Columbia University Press, 2000.

[ElHagePeronnyGriebelBelzung] El Hage, Wissam, Sylvie Peronny, Guy Griebel, Catherine Belzung. "Impaired memory following predatory stress in mice is improved by fluoxetine." Progress in Neuro-Psychopharmacology & Biological Psychiatry 28 (2004) 123 - 128.

[ElHageGriebelBelzung] El Hage, Wissam, Guy Griebel, and Catherine Belzung. "Long-term impaired memory following predatory stress in mice." Physiology & Behavior 87 (2006) 45 - 50.

[Zoladz] Zoladz, Phillip R. "An ethologically relevant animal model of posttraumatic stress disorder: Physiological, pharmacological and behavioral sequelae in rats exposed to predator stress and social instability." Graduate dissertation, University of South Florida. 2008.

[Stam] Stam, Rianne. "PTSD and stress sensitisation: A tale of brain and body Part 2: Animal models." Neuroscience & Biobehavioral Reviews Volume 31, Issue 4 (2007) 558 - 584.

[Stauth] Stauth, David. "Sharks, wolves and the 'ecology of fear'." 10 Nov. 2010. Accessed 17 March 2013.

[Salmonellosis] "Salmonellosis." Michigan Department of Natural Resources.

[bats] "Continued Rain, Snowpack Leaves Animals Hungry." Associated Press 23 Apr. 2006. CBS 13/UPN 31.

[Heidorn] Heidorn, Keith C. "Ice Storms: Hazardous Beauty." The Weather Doctor. 12 Jan. 1998, revised Dec. 2001.

[UCLA] UCLA Animal Care and Use Training Manual. UCLA Office for the Protection of Research Subjects.

[Nuffield] Nuffield Council on Bioethics. Ethics of Research Involving Animals. May 2005.

[Wilcox] Wilcox, Christie. "Bambi or Bessie: Are wild animals happier?" Scientific American Blogs. 12 April 2011. [For further discussion of this article, see this Felicifia thread. I think Christie understates the brutality of life on factory farms, but her points about wild animals are well taken.]

[BourneEtAl] Bourne, Debra C., Penny Cusdin, and Suzanne I. Boardman, eds. Pain Management in Ruminants. Wildlife Information Network. Mar. 2005.

[Cumming] Cumming, Jeffrey M. "Horn fly Haematobia irritans (L.)." Diptera Associated with Livestock Dung. North American Dipterists Society. 18 May 2006.

[BBC] "Fierce Ants Build 'Torture Rack'." BBC News 23 April 2005.

[Gould] Gould, Stephen Jay. "Nonmoral Nature." Hen's Teeth and Horse's Toes: Further Reflections in Natural History. New York: W. W. Norton, 1994.

[insect-pain] See, for instance, the following review articles: (1) Smith, Jane A. "A Question of Pain in Invertebrates." ILAR Journal 33.1-2 (1991). (2) Tomasik, Brian. "Can Insects Feel Pain?" Essays on Reducing Suffering. 2009.

[Williams] Williams, C. B. Patterns in the Balance of Nature and Related Problems. London: Academic Press, 1964.

[SchubelButman] Schubel, J. R. and Butman, C. A. "Keeping a Finger on the Pulse of Marine Biodiversity: How Healthy Is It?" Pages 84-103 of Nature and Human Society: The Quest for a Sustainable World. Washington, DC: National Academy Press, 1998.

[SolbrigSolbrig] Solbrig, O. T., and Solbrig, D. J. Introduction to Population Biology and Evolution. London: Addison-Wesley, 1979.

[Herbert] Herbert, Thomas J. "r and K selection." Accessed 17 March 2013.

[ClarkeNg] Clarke, Matthew and Ng, Yew-Kwang. "Population Dynamics and Animal Welfare: Issues Raised by the Culling of Kangaroos in Puckapunyal." Social Choice and Welfare 27:2 (pp. 407-22), 2006.

[Ng] Ng, Yew-Kwang. "Towards Welfare Biology: Evolutionary Economics of Animal Consciousness and Suffering." Biology and Philosophy 10.3 (pp. 255-85), 1995.

[Groff and Ng] Groff, Zach and Ng, Yew-Kwang. "Does suffering dominate enjoyment in the animal kingdom? An update to welfare biology". Biology and Philosophy, 2019.

[Sagoff] Sagoff, Mark. "Animal liberation and environmental ethics: Bad marriage, quick divorce." Osgoode Hall Law Journal 22, p. 297 (1984).

[Hapgood] Hapgood, Fred. Why males exist: an inquiry into the evolution of sex. Morrow (1979).

[EFSA] Animal and Welfare Scientific (AHAW) Panel. "Aspects of the biology and welfare of animals used for experimental and other scientific purposes." EFSA Journal 292, 1-136 (2005).

[DoodyPaull] Doody, J. Sean and Paull, Phillip. "Hitting the Ground Running: Environmentally Cued Hatching in a Lizard." Copeia: March 2013, Vol. 2013, No. 1, pp. 160-165.

[StevensEtAl] Stevens, Donald E., David W. Kohlhorst, Lee W. Miller, and D. W. Kelley. "The Decline of Striped Bass in the Sacramento-San Joaquin Estuary, California." Transactions of the American Fisheries Society 114.1 (pp. 12-30), 1985.

[Tomasik-short-lived] Tomasik, Brian. "Fitness Considerations Regarding the Suffering of Short-Lived Animals." Essays on Reducing Suffering. First written: 30 June 2013; last updated: 9 Feb. 2015.

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[MitchellThompson] Mitchell, T. and Thompson, L. (1994). "A Theory of Temporal Adjustments of the Evaluation of Events: Rosy Prospection and Rosy Retrospection." In C. Stubbart, J. Porac, and J. Meindl, eds., Advances in Managerial Cognition and Organizational Information-Processing, 5 (pp. 85-114). Greenwich, CT: JAI press.

[Singer] Singer, Peter. "Food for Thought." [Reply to a letter by David Rosinger.] New York Review of Books 20.10 (1973).

[Everett] Everett, Jennifer. "Environmental Ethics, Animal Welfarism, and the Problem of Predation: A Bambi Lover's Respect for Nature." Ethics and the Environment 6.1 (2001): 42-67.

[Cowen] Cowen, Tyler. "Policing Nature." 19 May 2001.

[Pimentel] Pimentel, David. "Pesticides and Pest Control." In Peshin, Rajinder and Dhawan, Ashok K., eds. Integrated Pest Management: Innovation-Development Process. Netherlands: Springer, 2009.

[Tomasik-insecticides] Tomasik, Brian. "Humane Insecticides: A Cost-Effectiveness Calculation." Essays on Reducing Suffering. 2009.

[MathenyChan] Matheny, Gaverick and Chan, Kai M. A. "Human Diets and Animal Welfare: The Illogic of the Larder." Journal of Agricultural and Environmental Ethics, 18:6 (pp. 579–94), 2005.

[Broom] Broom, D. M. "Animal Welfare: Concepts and Measurement" Journal of Animal Science, 69:10 (pp. 4167-4175), 1991.

[Drake] Estimates of the fraction of planets with life that go on to produce intelligence can be found in the literature on the Drake equation.

[Burton] Burton, Kathleen. "NASA Presents Star-Studded Mars Debate." 25 Mar. 2004.

[Meot-NerMatloff] Meot-Ner, M. and Matloff, G. L. "Directed Panspermia: A Technical and Ethical Evaluation of Seeding the Universe." Journal of the British Interplanetary Society 32 (pp. 419-23), 1979.

[Greger] Greger, Michael. "Why Honey Is Vegan." Satya Sept. 2005.


  1. Ed Gracely validly questions some of the numbers in Hapgood's passage, saying: "I doubt the quoted line that a pigeon can have 150 chicks or a mouse 1,000 kits is realistic. Even a mouse that bred every 3 weeks, had 10 pups each time, and lived two years would not attain half that. And pigeons have typically 2 eggs at a time, breed a few times a year, and live up to 10 years in the wild." Perhaps Hapgood was giving outliers rather than typical numbers of offspring per mother?  (back)